The present invention relates to helmets in general and in particular to collapsible helmets including a number of segments hinged in a manner movable between an expanded operative position and a folded inoperative position.
Personnel engaged in occupations or activities with high levels of danger are required to wear headgear to protect the wearers' heads against impact. Such headgear typically provides one of two levels of protection depending on which parts of the wearers' head are to be protected. The first level of protection is provided by "half helmets" for protecting the crown of a wearer whereas the second level of protection is provided by "full helmets" for protecting both the crown and the face of the wearer.
Such headgear typically includes a rigid shell helmet with a flexible internal rigging for supporting the shell in spaced relation to the wearers' heads. Rigid shell helmets suffer from a number of disadvantages. First, that they are relatively heavy when worn. Second, that they are inconvenient to carry when not in use. And third, they are inconvenient to store when not in use.
A number of collapsible helmets have been suggested to overcome some of these disadvantages as now described hereinbelow:
U.S. Pat. No. 3,987,495 to Holley describes a motorcycle helmet having two halves which may be detachably secured together for use or separated for easy storage. The halves come together at the central vertical plane that extends from the front of the helmet to the rear and thereby divides it into a right half and a left half that are mirror images of each other. PA1 U.S. Pat. No. 4,587,676 to Estadella describes a collapsible helmet including two supplemental portions which are mutually joined at two pivot points. The supplemental portions rotate about the rotating points and engage one inside the other in a folded position and engage along a line which extends parallel to a line which defines the bottom perimeter of the helmet. PA1 U.S. Pat. No. 4,827,537 to Villa describes a helmet having a plurality of segments which are interhinged for swinging movement between an expanded operating position and a collapsed non-operating position. The segments have cooperating ribs and recesses to maintain them in the expanded operating position. PA1 U.S. Pat. No. 4,091,470 to Ryunishin describes a collapsible helmet composed of several inwardly curved fan-shaped sections. The helmet can be folded into a nested position so as to assume the size of one of the sections.
Such developments suffer from a number of disadvantages including that they typically include a large number of elements and complicated mechanisms, they are cumbersome during conversion from their expanded operative positions to their folded inoperative positions and vice versa, and packages formed by the collapsible helmets are large and awkwardly shaped.
Therefore, there is a need for a collapsible helmet which overcomes the disadvantages of conventional collapsible helmets.